Space telegraphy.



No. 879,532. PATENTED FEB. 18, 1908.

L. DE FOREST.

SPACE TELEGRAPHY. APPLIGATION FILED JAN. 29. 1907.

ablyo other sourceofelectrical current of UNITED STATES PATENT OFFICE.

LEE DE FOREST, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO DE FOREST 4 RADIO TELEPHONE 00., A CORPORATION OF NEW YORK.

sracn rarinqnam.

To all whom it may concern:

Be it known that 1, LEE DE FOREST, a citizen of the United States, and a resident of New 'York, in the county of New York and 5 State of New York, have invented a new and useful Improvement in Space Telegraphy, of which the following is a specification. My invention relates to wireless telegraph receivers or oscillation detectors of a t pc heretofore described in my prior Letters atent NOS. 824,637, June 26, 1906 and 836,070, November 13, 1906. I

Theobjects of m invention are to increase the sensitiveness o oscillation detectors comprisi in their construction a gaseous medium y means of the structural features and circuit arrangements which are hereinafter more fullydescribed.

My invention will be described with reference to the drawings which accompany and form a part of the present specification, although it is to be understood that many modifications may be made in the a paratus and systems herein described wit out departing from the principles of my invention.

In the drawings, Figure 1 represents in diagram a wireless tele raph receiving system comprising an oscilla structed and connected in accordance with 80 the present invention and Fig. 2 represents a space telegraph receiving system having a modified form of oscillation detector connected therein in a manner which constitutes one of the subjects matter of said invention.

V I, E is an elevated conductor system including. theelcvated conductor V, earth connection E, and primary I, of the transformer the secondary I of which forms .part of the tuned receiving circuit I .0. It will be 40 understoodof course that the aforesaid tuned receiving circuit may be associated, with the elevated conductor system in any suitable manner. D re resents an evacuated vessel, preferi glass, having sealed therein three conducting members, F, a and b, in Fig.11 and F,.a and bin Fi .2. The conducting member-or electrode is-shown as consisting of a filament, preferably ofmetal, which is connected in series with the battery A or strength to heat said filament, preferably-to incandescence. The conducting me ber t, which may .be aplate' of platinumshas one Specification of Letters Patent.

' Application file d January 28. 1907- Serial No. 355662.

I ion detector consufficient:

Patented Feb. 18, 1908.

I shaped member a, which may be formed of latinum wire, and which has one end i lirought out to the terminal 1. The local re ceiving circuit, which includes the battery '13, I or other suitable source of electromotive force, and the signal indicating device T, which may be a telephone receiver, has its 5 terminals connected to the late I) and filament F at the points 3 and 4 res ectively. The means for conveyi the oscillations to I be detected to the osc' ation-detector, are i the conductors which connect the filament F and grid a to the tuned receiv' l as shown, said conductors pass 1 minals 2 and 1 to f denser C. t I have determined experimentally that the presence of the conducting member a, which om the terthe armatures of the conas before stated may be 'd-shaped, increases the sensitiveness o the oscillation detector and, inasmuch as the explanation of this phenomenon is exceedingly com lex and at best would be merely tentative, donot deem it necessary herein to enter into a detailed statement of What 'I believe to be the probable explanation.

In associating an oscillation detector of the above mentioned type, said detector being now commonly. known as the audion, with a closed tuned circuit, it w be noted by reference to Fig. 2, that the secondary Lcloses a circuit containing a batter shown at B through the'electrode b; con 0/ and the conducting gaseous medium intervening between said electrode and mom,- ber. Also by reference to Fig. 1, it will be seen that a similar closed circuit exists between said battery, and the electrode b and conduct member a. In order to close,

current from the aforesai battery therethrough, or to prevent thedevelopment of a inthesound-prodpced in the telephone T from said; battery, I insert the in said otherwise mechanically I end brought out to the terminal 3. Inter-' l posed between the members F and b is agriducting member.

difference of potential between the members 7 increase in circuit and,

, ,sr each of said circuits to the cpassage of-direct- (1 a a I stance 1 when said condenser is present over the sounds produced therein under the same conditions when said condenser is not'employed.

It will be understood that theicircuit arrangements herein described with reference to the particular forms of audion herein dis-' closed may with advantage also be employed with various other types of audion.

I claim: 1. An oscillation detector comprising an evacuated vessel, an electrode inclosed therein, means for heating said electrode, a second electrode inclosed within said vessel, a local' circuit having its terminals electrically connected to said electrodes, a conductin mem: ber inclosed within said vessel and ocated between said electrodes, and means for coni vc'ying the oscillations to be detected to the iirst mentioned electrode and said conductmg'member.

2. An oscillation detector comprising an evacuated vessel, two electrodes inclosed conducting material electrodes,

signal indicating device, material sealed in said vessel .and interposed detected to said within said vessel, means for heating one of said electrodes, and a'conducting member terminals connected to said filament and electrode,- respectively,

said local circuit inclu a source of electromotive force and a a grid of conducting between said filament and electrode, and means for conve 'rig the oscillations to be ament and grid. 5. oscillation detector comprising an evacuated vessel, an electrode inclosed therein, means for-heating said electrode, a second electrode inclosed within said vessel, a local circuit having its terminals connected tosaid electrodes, within said a closed circuit for conv eying the oscillations to be detected to saidfirstmentioned electrode and conducting member,

and a condenser in saidclosed circuit.

6. An' oscillation evacuated vessel, two electrodes inclosed therein, means for heatin one of said electrodes, a conducting merrilier inclosed within said vessel and into osed between said electrodes, means for esta lishing a difierence of electrical potential between said electrodesgand means for-preventing said consaid electrodes, means ed member of electrodes and means evacuated vessel, two

a conducting member inclosed vessel andlocated between said,

detector comprising an ducting member from becoming electrically charged.

7. Anoscillation detector comprising an r a sensitive conthree conducting a closed oscillaevacuated vessel inclosing ducting gaseous medlum, members inclosed therein,

tion circuit, a circuit connecting an element 4 of said oscillation circuit with two'of said members, a condenserin said circuit, av sig-- nal-indicatingdevice, and a circuit connecting said device with one 0% said two members and with the third member. I

8. .An oscillation detector comprising an evacuated vessel, two electrodes inclosed therein, means for heating one of said elec- "trodes, a conducting member inclosed within said vessel and interposed between said electrodes, means for establishing a difference of electrical potential between said electrodes and means for preventmg the establishment of a differenceof electrical potential between one of said electrodes and said conducting member. e

9. An oscillation detector comprising an evacuated vessel, two electrodes inclosed therein, means for heating one of said electrodes, a grid of conducting material inclosed within said vessel and interposed between for establishing a dif ierence of electrical potential between said for preventing said electrically charged.

detector comprising an electrodes inclosed therein, means for heating one of said elecgrid' from becoming 10. An oscillation trodes; a grid of conducting material inclosed within said vessel and interposed between said electrodes, means for establishing, difference of electrical electrodes and means for preventingthe establishment of a diilerence of electrical potential between one of said electrodes and said grid. g

11. An oscillation detector comprising an evacuated vessel, an electrode incloseditherein, means for heating said electrode, a second electrode inclosed within said vessel, a local circuit having its terminals electrically connected to said electrodes, a grid of cond ing material inclosed within said vessel and located between said electrodes, and means potential between said for conveying the oscillations to be detected to the heated electrode and grid.

12. An oscillation detector comprising an evacuated vessel, an electrode inclosed therein, means for heating said electrode, a second electrode inclosed within said vessel, a local circuit having its terminals connected to said electrodes a grid of conducting material in;

closed wit said vessel and located between said electrodes, a closed circuit forccnveying the oscillations to 4 closed circuit.

v 13, .An oscillation detector comprising an be detected to the heated electrode and grid, andacondenser in said electrode inclosed within said vessel, a local conducting member inclosed within said vessel and interposed between said electrodes.

H inclosed within between said electrodes, a'local circuit con-- said vessel and interposed between said elecf within said vessel, means for heating one of 'Sa1d electrodes, a conductlng member 1n- -ing material inclosed within said vesselanda 17. Anoscillation detector comprising an evacuated vessel, an electrode inclosed therein, means for heating sa d electrode, a second circuit having its terminals electrically dbnnected to'said electrodes, .said local circuit including'a source of electromotive force and" a signal indicating device, a grid of conductlocat'ed between said electrodes, and means for conveying the oscillations to be detected to the heated electrode and grid.

l4. oscillation detector comprising an evacuated vessel, two electrodes, one of- .which is'a filament, inclosed within said ves-" sel, means for heating said filament, anda 15. An oscillation detector comprising an evacuated vessel, two electrodes inclosed within said vessel,-me'ans for heating one of said electrodes, a grid of conducting material said vessel and interposed trodes.

evacuated vessel; two' electrodes inclosed closed within said vessel and interposed be tween s'aid electrodes, and a local circuit including a source of electromotive force con necting said electrodes;

v18. An oscillation detector comprising an evacuated vessel, two electrodes inclosed within said'vessel, means for heating one of.

said electrodes, 9. grid of conducting material inclosed within said vessel and interposed between said electrodes, a local circuit including a source of electromotive force connecting said electrodes and a signal indicating device associated with said local circuit. 7

19. An oscillation detector comprising an evacuatedv vessel, twoelectrodes, one of which is a filament, inclosed within said vessel, means for heating said filament, a grid of conducting material inclosed within said vessel and interposed between said electrodes and a local circuit including asource of electromotive force connecting said electrodes.

20. An oscillation detector comprising an evacuated Vessel, two electrodes inclosed therein; means for heating one of said electrodes, a conducting member inclosed within.

said vessel, a closed oscillation circuit, a circuit connecting one element of said oscilla- 1 tion circuit with one of said electrodes and said conducting member, and a condenser in said l llcllltn 21; An oscillation detector comprising an evacuated vessel, two electrodes inclosed there1n,fmeans for heating one of saidelectrodes, a conducting member inclosed within said vessel, a closed oscillation circuit, a circuit connecting one element of said oscillation circuit with one offsaid electrodes and said conducting member, a condenser in said circuit, a signal indicating device and a' circuit connecting said device With the other of said electrodes and said conducting member.

In testimony whereof, I have hereunto siibscribed my name this 21st day of Dec, 1906.

, LEE DE FOREST.

Witnesses:

THOMAS I. GALLAGHER, HANS W. Gon'rzn. 

